package k2_oop.p7_javaLang.demo01;

import java.util.Arrays;

public class UseSystem {

    public static void main(String[] args){

//        System.out.println("做标准输出流");

        //通过业务逻辑来判定正确还是错误
//        System.err.println("做标准错误输出流");

        //退出JVM 退出码任意，只要是int类型即可
//        System.exit(0);

//        long startTime = System.currentTimeMillis();
//
//        for (int i = 0; i <100000 ; i++) {
//            System.out.println(i);
//        }
//
//        long endTime = System.currentTimeMillis();
//
//        System.out.println(endTime-startTime);

        int[] nums = {100,200,300,400,500,600,700,800,900};
        int[] numsNew = new int[nums.length];

        System.arraycopy(nums,0,numsNew,0,nums.length);
        System.out.println(Arrays.toString(numsNew));

        int[] numsNew1 = {3,6,5,8,1,2,3,9,10,2,3,48,1};
        System.arraycopy(nums,3,numsNew1,4,4);
        System.out.println(Arrays.toString(numsNew1));

        System.arraycopy(nums,6,nums,0,3);
        System.out.println(Arrays.toString(nums));

    }

}
